For the updates in the past year go here. For a full list of updates before February 8, 2018, go here.

Curiosity

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Since my January 22, 2019 update, Curiosity finally drove down off of Vera Rubin Ridge into a valley between the ridge and the lower slopes of Mt Sharp. The Mars Reconnaissance Orbiter (MRO) overview on the right has been annotated by me to show the rover’s travels (shown by the yellow dotted line), with its proposed route indicated by the red dotted line. The yellow lines indicate approximately the terrain seen in the panorama above. The panorama was created from images taken on Sol 2016.

The valley that Curiosity is presently traversing is dubbed “the clay unit” or “the clay-bearing unit” by the geologists, based on its make-up determined from orbital data. So far they have found this terrain to be “some of the best driving terrain we’ve encountered in Gale Crater, with just some occasional sandy patches in the lee of small ridges.” Initially they had problems finding any rocks or pebbles large enough for the instruments to use for gathering geological data. For the past week or so, however, they have stopped at “bright exposure of rock” where some bedrock was visible, giving them much better material to work with.» Read more

NASA today officially announced that the rover Opportunity — built to last 90 days — is dead, only three weeks after celebrating its fifteenth anniversary operating on the Martian surface.

This is what project scientist Steve Squyres had to say about the rover’s finish:

“When I saw that the storm had gone global, I thought this could be it,” said Squyres, explaining that Opportunity was a solar-powered vehicle and needed the sun for energy. “To have Opportunity – designed for 90 days – taken out after fourteen and a half years by one of the most ferocious dust storms to hit the planet in decades, you have got to feel pretty good about it.”

He said: “It was an honorable end, and it came a whole lot later than any of us expected.”

The article gives some nice background into the personal stories of many of the scientists who worked on Opportunity for all those years. For some overall scientific context, see this article. Or you can read the many rover updates I have written in the past two and a half years, which will give you a detailed sense of Opportunity’s travels along the rim of Endeavour Crater.

Rumors today say that during a press conference tomorrow NASA will announce that it is closing the books on the incredibly successful rover Opportunity.

From the first link:

NASA said Tuesday it will issue a final series of recovery commands, on top of more than 1,000 already sent. If there’s no response by Wednesday — which NASA suspects will be the case — Opportunity will be declared dead, 15 years after arriving at the red planet.

Opportunity was supposed to last 90 days. Instead, it lasted just under fifteen years, drove 28 miles, and saw far more of the Martian surface than anyone ever expected.

Summary: Curiosity begins journey off of Vera Rubin Ridge. Opportunity’s silence is now more than seven months long, with new dust storms arriving. Yutu-2 begins roving the Moon’s far side.

Before providing today’s update, I have decided to provide links to all the updates that have taken place since I provided a full list in my February 8, 2018 update. As I noted then, this allows my new readers to catch up and have a better understanding of where each rover is, where each is heading, and what fascinating things they have seen in the past few years.

These updates began when I decided to figure out the overall context of Curiosity’s travels, which resulted in my March 2016 post, Pinpointing Curiosity’s location in Gale Crater. Then, when Curiosity started to travel through the fascinating and rough Murray Buttes terrain in the summer of 2016, I stated to post regular updates. To understand the press releases from NASA on the rover’s discoveries it is really necessary to understand the larger picture, which is what these updates provide. Soon, I added Opportunity to the updates, with the larger context of its recent travels along the rim of Endeavour Crater explained in my May 15, 2017 rover update.

The Opportunity science team reported today that they have noted an increase in local dust storm activity just south of the silent rover.

The storm is expected to increase in opacity (tau) at the rover site to greater than 1.5 over the next few days. No signal from Opportunity has been heard since Sol 5111 (June 10, 2018) during the historic global dust storm. Opportunity likely experienced a low-power fault, a mission clock fault and an up-loss timer fault. Since the loss of signal, the team has been listening for the rover over a broad range of times, frequencies and polarizations using the Deep Space Network (DSN) Radio Science Receiver.

This activity, plus the fact that they have still not been able to re-establish contact with the rover during the recent dust devil season, when they had hoped a devil might clear the dust off the solar panels, bodes very bad for the rover. The Curiosity team is also seeing more dust activity, and notes that these dust storms will also act to reduce the number of dust devils.

Curiosity

The traverse map on the right, unchanged from my last rover update on July 17, 2018, shows almost all of Curiosity’s travels on Vera Rubin Ridge. The yellow dotted line is the oldest travel, up onto the ridge and then back down to get a successful drill sample. The green dotted line shows the rover’s return back up onto the top of the ridge, where it attempted and failed to drill into the ridge’s top layer, then experienced a serious computer issue in mid-September that essentially shut down science operations for about five weeks.

NASA has decided to continue through January its effort to both listen and send signals to Opportunity in the hope of bringing it to life.

The 45-day deadline passed late last week. But NASA will continue active listening — a strategy that involves both sending commands to Opportunity and listening for any peeps the six-wheeled robot may make — for several more months at least, agency officials announced yesterday. “After a review of the progress of the listening campaign, NASA will continue its current strategy for attempting to make contact with the Opportunity rover for the foreseeable future,” NASA officials wrote in a mission update yesterday. “Winds could increase in the next few months at Opportunity’s location on Mars, resulting in dust being blown off the rover’s solar panels,” they added. “The agency will reassess the situation in the January 2019 time frame.”

This is exactly what the planetary scientists wanted. Their hope is that, with the beginning of dust devil season in November, the chances will then increase for removing the dust that likely covers the rover’s solar panels. It is thought that the rover has a better shot at coming back to life during this time period.

While NASA will continue to listen for activity from Opportunity for many more months, its active effort to signal the Mars rover is about to end.

After more than a month, Opportunity has not responded to those commands, and that active listening effort will soon end. “We intend to keep pinging Opportunity on a daily basis for at least another week or two,” said Lori Glaze, acting director of NASA’s planetary science division, during a presentation Oct. 22 at the annual meeting of the American Astronomical Society’s Division for Planetary Sciences here.

Glaze said that a factor in ending the active listening campaign is to prepare for the landing of the InSight spacecraft on Mars Nov. 26. “We want to wind that down before InSight gets to Mars and make sure all our orbital assets are focused on a successful landing of InSight,” she said.

That schedule is consistent with previous plans for attempting to restore contact with Opportunity. NASA said Aug. 30 that, once skies cleared sufficiently, it would attempt active listening for 45 days. “If we do not hear back after 45 days, the team will be forced to conclude that the sun-blocking dust and the Martian cold have conspired to cause some type of fault from which the rover will more than likely not recover,” John Callas, Opportunity project manager, said in a statement outlining those plans.

I would not be surprised if they do try to signal the rover a few more times, in January after the busy fall period when there are a lot of planetary probes needing access to the Deep Space Network. Even so, it appears the rover’s life is finally at an end, fourteen years past its originally planned lifespan of only 90 days.

The Curiosity engineering team have decided to switch on-board computers in effort to figure out why the rover has been unable to store and send any data since September 15.

After reviewing several options, JPL engineers recommended that the rover switch from Side B to Side A, the computer the rover used initially after landing.

The rover continues to send limited engineering data stored in short-term memory when it connects to a relay orbiter. It is otherwise healthy and receiving commands. But whatever is preventing Curiosity from storing science data in long-term memory is also preventing the storage of the rover’s event records, a journal of all its actions that engineers need in order to make a diagnosis. The computer swap will allow data and event records to be stored on the Side-A computer.

Side A experienced hardware and software issues over five years ago on sol 200 of the mission, leaving the rover uncommandable and running down its battery. At that time, the team successfully switched to Side B. Engineers have since diagnosed and quarantined the part of Side A’s memory that was affected so that computer is again available to support the mission. [emphasis mine]

As indicated by the highlighted paragraph, the switch does carry some risk. Though they say they have isolated the problems with the A computer, they might be surprised when they turn it on.

Meanwhile, silence continues from Opportunity. After fourteen years of almost continuous rover operations on Mars, the United States have been roverless now for more than two weeks.

Mars Reconnaissance Orbiter has taken a picture through the fading Martian dust storm that spots Opportunity about halfway down Perseverance Valley in the rim of Endeavour Crater.

Engineers have been increasing the number of times per day they are attempting to communicate with the rover, so far all to no avail. The picture thus only really tells us that the storm is lifting and that MRO’s high resolution camera is operating normally after three months of limited picture taking because of the dust storm.

The science team is also sending a command three times a week to elicit a beep if the rover happens to be awake, and will soon be expanding the commanding to include “sweep and beeps” to address a possible complexity with certain conditions within the mission clock fault. These will continue through January of 2019.

The dust storm on Mars continues its decay with atmospheric opacity (tau) over the rover site continuing to decrease. Once the tau has fallen below an estimated measurement of 1.5 twice – with one week apart between measurements – a period of 45 days will begin representing the best time for us to hear from the rover.

This also represents the best time to attempt active commanding during a specific mission clock fault condition. Back during the attempted recovery of the Spirit rover, a technical issue required the team to actively command the rover to communicate. Opportunity has no such issue; if we hear from it, it will likely be from listening passively as we have been, and as we will continue to do through January.

We will also actively attempt to command the rover to communicate during the 45-day listening period to cover the clock fault condition. After that, we will report to NASA on our efforts.

In other words, the final 45 day listening period will not officially begin until the Martian atmosphere has cleared more, rather than begin about now and thus end about the middle of November, before the dust devil season begins.

The reasons they want to listen through the dust devil season is that they believe it likely that the rover’s solar panels have been covered with dust, and will need a nearby dust devil to blow this away. This might sound unlikely, but it has happened several times with both Spirit and Opportunity during both of their spectacularly extended missions.

Members of Opportunity’s engineering team recommended a different plan, the person close to the mission says. Their idea was to actively try to communicate with Opportunity until the end of January 2019 — the end of the seasonal cleaning period. After that, they suggested passive listening until the end of 2019. But these recommendations were ignored by management in order to save money, this person says, meaning the agency could be risking abandoning a still-functioning rover. The Opportunity team reportedly didn’t receive formal notice of the plan until “minutes before JPL published its press release,” according to The Atlantic.

It appears that some on the science team do not feel that the present plan to listen closely for only 45 days, through mid-October, is sufficient, as it will likely require a dust devil to clear Opportunity’s solar panels, and dust devil season will not begin until November.

However, it is very likely wrong to blame the resistance by NASA management to this plan solely to a desire to save money. There are other considerations, such as tying up the Deep Space Network for this one rover when, as I noted yesterday, the October to January time period will be a very very very busy time for that network, with many important new planetary probe events. Seven different spacecraft will either be landing or doing fly-bys on four different solar system targets during that time. Tying the network up to listen for Opportunity will likely not work.

It seems to me that Opportunity should be recovered, if possible, but it also must receive a lower priority during this time period. After New Horizons’ January 1st fly-by of Ultima Thule it might be possible to devote more time then to listening, but I can see the logic, at least in this context, for reducing the listening time from October to January.

The Opportunity science team today provided a new update on the rover, noting that it remains silent even as the Martian dust storm is clearing.

With skies clearing, mission managers are hopeful the rover will attempt to call home, but they are also prepared for an extended period of silence. “If we do not hear back after 45 days, the team will be forced to conclude that the Sun-blocking dust and the Martian cold have conspired to cause some type of fault from which the rover will more than likely not recover,” said Callas. “At that point our active phase of reaching out to Opportunity will be at an end. However, in the unlikely chance that there is a large amount of dust sitting on the solar arrays that is blocking the Sun’s energy, we will continue passive listening efforts for several months.”

The additional several months for passive listening are an allowance for the possibility that a Red Planet dust devil could come along and literally dust off Opportunity’s solar arrays. Such “cleaning events” were first discovered by Mars rover teams in 2004 when, on several occasions, battery power levels aboard both Spirit and Opportunity increased by several percent during a single Martian night, when the logical expectation was that they would continue to decrease. These cleaning dust devils have even been imaged by both rovers on the surface and spacecraft in orbit (see https://mars.nasa.gov/resources/5307/the-serpent-dust-devil-of-mars/).

It appears however that if nothing is heard from Opportunity by sometime in mid-October, they will be very prepared at that time to begin shutting down ground-based operations here on Earth.

Link here. This article from JPL provides a detailed status report on the rover, as well as what will happen if they should regain communications.

After the first time engineers hear from Opportunity, there could be a lag of several weeks before a second time. It’s like a patient coming out of a coma: It takes time to fully recover. It may take several communication sessions before engineers have enough information to take action.

The first thing to do is learn more about the state of the rover. Opportunity’s team will ask for a history of the rover’s battery and solar cells and take its temperature. If the clock lost track of time, it will be reset. The rover would take pictures of itself to see whether dust might be caked on sensitive parts, and test actuators to see if dust slipped inside, affecting its joints.

Once they’ve gathered all this data, the team would take a poll about whether they’re ready to attempt a full recovery.

Even if engineers hear back from Opportunity, there’s a real possibility the rover won’t be the same. The rover’s batteries could have discharged so much power — and stayed inactive so long — that their capacity is reduced. If those batteries can’t hold as much charge, it could affect the rover’s continued operations. It could also mean that energy-draining behavior, like running its heaters during winter, could cause the batteries to brown out.

They remain hopeful, but this article is clearly meant to prepare the public for the possibility that Opportunity’s long journey on Mars might have finally ended.

In my normal routine to check out the periodic posting of new high resolution images from Mars Reconnaissance Orbiter (MRO), the August 1 update brought what at first was a disturbing surprise. If you go to the link you will see that a large majority of the images show nothing by a series of vertical lines, as if the high resolution camera on MRO has failed.

Yet, scattered among the images were perfectly sharp images. I started to look at these images to try to figure out the differences, and quickly found that the sharp images were always of features in high latitudes, while the blurred images were closer to the equator.

The August 1 image release covered the June/July time period, when the on-going Martian dust storm was at its height. The images illustrate also where the storm was most opaque, closer to the equator.

The next few updates, which occur every three weeks or so, should show increasing clarity as the storm subsides. And the storm is subsiding, according to the latest Opportunity update. The scientists have still not re-established contact with the rover, and do not expect to for at least a month or more, but they are finding that the atmospheric opacity at Endeavour Crater seems to be dropping.

The Martian global dust storm that started in mid-June and has left the rover Opportunity with little power appears to be finally clearing.

Don’t expect any word from Opportunity however for at least a month. The storm might be dying off, but it will take time for the dust to settle out of the atmosphere, especially in Mars’s light gravity.

Summary: Curiosity climbs back up onto Vera Rubin Ridge to attempt its second drillhole since drill recovery, this time at a spot on the ridge with the highest orbital signature for hematite. Opportunity remains silent, shut down due to the global dust storm.

Curiosity

In the almost two months since my May 23, 2018 update, a lot has happened, much of which I covered in daily updates. Curiosity found a good drill spot to once again test the new drilling techniques designed by engineers to bypass its stuck drill feed mechanism, and was successful in getting its first drill sample in about a year and a half. The rover then returned uphill, returning to a spot on Vera Rubin Ridge that, according to satellite data, has the highest signature for hematite on the entire ridge. The light green dotted line in the traverse map to the right shows the route Curiosity has taken back up onto Vera Rubin Ridge. The red dotted line shows the original planned route off the ridge and up Mount Sharp.» Read more

Data from orbit and from Curiosity at Gale Crater confirms that the dust storm that has shut down Opportunity is now a global storm, encircling Mars.

The Martian dust storm has grown in size and is now officially a “planet-encircling” (or “global”) dust event.

Though Curiosity is on the other side of Mars from Opportunity, dust has steadily increased over it, more than doubling over the weekend. The sunlight-blocking haze, called “tau,” is now above 8.0 at Gale Crater — the highest tau the mission has ever recorded. Tau was last measured near 11 over Opportunity, thick enough that accurate measurements are no longer possible for Mars’ oldest active rover.

This will be first global storm to occur on Mars since Curiosity landed in 2012, thus giving scientists the best opportunity to study such an event.

Meanwhile, Opportunity remains silent. This does not mean it is dead, but that it doesn’t have enough sunlight to charge its batteries. It might die during this storm if the storm lasts long enough, but we won’t know one way or the other until the storm finally eases.

A growing Martian dust storm has forced the Opportunity science team to suspend science operations and to reconfigure the rover’s operations to increase its chances of surviving the storm.

In a matter of days, the storm had ballooned. It now spans more than 7 million square miles (18 million square kilometers) — an area greater than North America — and includes Opportunity’s current location at Perseverance Valley. More importantly, the swirling dust has raised the atmospheric opacity, or “tau,” in the valley in the past few days. This is comparable to an extremely smoggy day that blots out sunlight. The rover uses solar panels to provide power and to recharge its batteries.

Opportunity’s power levels had dropped significantly by Wednesday, June 6, requiring the rover to shift to minimal operations.

This isn’t Opportunity’s first time hunkering down in bad weather: in 2007, a much larger storm covered the planet. That led to two weeks of minimal operations, including several days with no contact from the rover to save power. The project’s management prepared for the possibility that Opportunity couldn’t balance low levels of power with its energy-intensive survival heaters, which protect its batteries from Mars’ extreme cold. It’s not unlike running a car in the winter so that the cold doesn’t sap its battery charge.There is a risk to the rover if the storm persists for too long and Opportunity gets too cold while waiting for the skies to clear.

In other words, there is a possibility that the rover might not make it through this period of low sunlight. Nonetheless, the rover did send four images down yesterday, though the four images are essentially dust filled, and are likely aimed at the far distance to help gauge the extent of the storm.

Summary: Curiosity drives down off of Vera Rubin Ridge to do drilling in lower Murray Formation geology unit, while Opportunity continues to puzzle over the formation process that created Perseverance Valley in the rim of Endeavour Crater.

Curiosity

Since my April 27, 2018 update, Curiosity has continued its downward trek off of Vera Rubin Ridge back in the direction from which it came. The annotated traverse map to the right, cropped and taken from the rover’s most recent full traverse map, shows the rover’s recent circuitous route with the yellow dotted line. The red dotted line shows the originally planned route off of Vera Rubin Ridge, which they have presently bypassed.

It appears they have had several reasons for returning to the Murray Formation below the Hematite Unit on Vera Rubin Ridge. First, it appears they wanted to get more data about the geological layers just below the Hematite Unit, including the layer immediately below, dubbed the Blunts Point member.

While this is certainly their main goal, I also suspect that they wanted to find a good and relatively easy drilling candidate to test their new drill technique. The last two times they tested this new technique, which bypasses the drill’s stuck feed mechanism by having the robot arm itself push the drill bit against the rock, the drilling did not succeed. It appeared the force applied by the robot arm to push the drill into the rock was not sufficient. The rock was too hard.

In these first attempts, however, they only used the drill’s rotation to drill, thus reducing the stress on the robot arm. The rotation however was insufficient. Thus, they decided with the next drill attempt to add the drill’s “percussion” capability, where it would not only rotate but also repeatedly pound up and down, the way a standard hammer drill works on Earth.

I suspect that they are proceeding carefully with this because this new technique places stress the operation of the robot arm, something they absolutely do not want to lose. By leaving Vera Rubin Ridge they return to the more delicate and softer materials already explored in the Murray Formation. This is very clear in the photo below, cropped from the original to post here, showing the boulder they have chosen to drill into, dubbed “Duluth,” with the successful drill hole to the right.» Read more

So what is it we are looking at in the image above? I have reduced the resolution slightly to fit it here, but you can see the full resolution image by clicking on the picture.

Is it a marble or granite kitchen counter? Nah, the surface is too rough.

Maybe it’s a modern abstract painting that we can find hanging in the Museum of Modern Art in New York. Nah, it has too much style and depth. Abstract art is much more shallow and empty of content.

Could it be a close-up of a just-opened container of berry-vanilla ice cream, the different flavors swirling and intertwined to enhance the eating experience? No, somehow it looks too gritty for ice cream.» Read more

Curiosity

Since my March 21, 2018 update, it has become apparent that the Curiosity science team has decided to extend the rover’s research on Vera Rubin Ridge far beyond their original plans. They have continued their travels to the northeast well past the original nominal route off the ridge, as indicated by the dotted red line on the traverse map above. Along the way they stopped to inspect a wide variety of geology, and have now moved to the north and have actually begun descending off the ridge, but in a direction that takes the rover away from Mount Sharp and its original route. As noted in their April 25 update,» Read more

Curiosity

Since my February 8, 2018 update, the Curiosity science team has apparently been loath to leave Vera Rubin Ridge. They had begun the trek to the northeast that would take them towards the exit ridge heading to the southeast, as indicated by the dotted red line on the traverse map above, but then continued past that planned route to continue to the northeast. Along the way they attempted to drill twice using an improvised approach that they hoped would bypass the drill’s stuck feed mechanism, without apparent success.

The panorama below is looking to the west and south, as indicated by the yellow lines in the image above.» Read more

The uncertainty of science: Last week, while I was flying to Israel, the Opportunity science team announced the discovery of strange aligned erosion lines, what they are calling stone stripes, in Perseverance Valley.

The ground texture seen in recent images from the rover resembles a smudged version of very distinctive stone stripes on some mountain slopes on Earth that result from repeated cycles of freezing and thawing of wet soil. But it might also be due to wind, downhill transport, other processes or a combination.

…On some slopes within the valley, the soil and gravel particles appear to have become organized into narrow rows or corrugations, parallel to the slope, alternating between rows with more gravel and rows with less.

The origin of the whole valley is uncertain. Rover-team scientists are analyzing various clues that suggest actions of water, wind or ice. They are also considering a range of possible explanations for the stripes, and remain uncertain about whether this texture results from processes of relatively modern Mars or a much older Mars.

For those who are regular readers of Behind the Black, you already knew about a variation of this discovery back in November 2017, from my regular rover updates. Then, they discovered aligned groves in the gravel that looked to me like slickensides, erosion patterns produced by glacial activity. The science team told me, however, that they were favoring wind, not ice, as a primary cause, though that conclusion was far from certain.

In the press release last week, they focused more on the aligned erosion patterns in the fine gravel that appear to align perpendicular to the slope. Though they think they have found a comparable Earth-based phenomenon that might explain these patterns, it appears that the science team remains just as unsure of their cause as they are for the rocks.

Summary: Curiosity remains on Vera Rubin Ridge, though it has begun moving toward the point where it will move down off the ridge. Opportunity remains in Perseverance Valley, though it has finally taken the north fork down.

Before providing today’s update, I have decided it is time to provide links to all previous updates, in chronological order. This will allow my new readers to catch up and have a better understanding of where each rover is, where each is heading, and what fascinating things they have seen in the past year and a half.

These updates began when I decided to figure out the overall context of Curiosity’s travels, which resulted in my March 2016 post, Pinpointing Curiosity’s location in Gale Crater. Then, when Curiosity started to travel through the fascinating and rough Murray Buttes terrain in the summer of 2016, I stated to post regular updates. To understand the press releases from NASA on the rover’s discoveries it is really necessary to understand the larger picture, which is what these updates provide. Soon, I added Opportunity to the updates, with the larger context of its recent travels along the rim of Endeavour Crater explained in my May 15, 2017 rover update.

Summary: Both rovers have moved little in the past month, Opportunity because it is in a good science location and because it must save energy during the winter and Curiosity because it is in a geological location so good the scientists appear to almost be going ga-ga over it.

Curiosity

In the month since my December 18 update, Curiosity has continued to head south rather than east as originally planned (as indicated by the dotted yellow line in the traverse map to the right). Moreover, the rover has not moved very much, because the science team has decided that there is just too much significant geology in this area on Vera Rubin Ridge, also part of a geological unit they have dubbed the Hematite Unit.

Right now the rover is located at an area they call “Region e,” one of the three patches I have also indicated on the image to the right. From the second update below:

This location is a slight depression with exposed fractured bedrock that appears more “blue” from orbit than the surrounding region. In addition, the orbital evidence and observations from the ground suggest that this location is similar to “Region 10” that we visited just last week, which was shown to have some pretty spectacular small-scale features that were of particular interest to many on the science team. As a result, the team was very excited to reach “Region e” and begin our scientific investigation!

The last few updates on the Curiosity mission update page indicate the excitement the geologists have for this site:» Read more

Curiosity

Since my November 16 update, Curiosity’s travels crossing Vera Rubin Ridge, a geological bedding plain dubbed the Hematite Unit, has continued apace. They however have not been following the route that had been planned beforehand, as shown by the yellow dotted line on the right. Instead, they have headed south, along the red dotted line. For the past week or so they have been doing a variety of research tasks in the same area, analyzing samples taken months before, studying sand deposits, and taking many images of some interesting rock layers.

I also suspect that the lack of movement in the past week is partly because they need to make some route-finding decisions. The planned yellow route shown above appears to be somewhat rough in the full resolution orbital image. While I suspect they will still head in that direction, I also think they are doing some very careful analysis of this route and beyond, to make sure they will not end up in a cul de sac where the rover will not be able to continue its climb of Mount Sharp.

Cool image time! The Mars Reconnaissance Orbiter (MRO) image on the right, reduced in resolution to post here, captures a distinctive fault line that cuts across some layered deposits. As noted by the MRO science team,

Some of the faults produced a clean break along the layers, displacing and offsetting individual beds (yellow arrow).

Interestingly, the layers continue across the fault and appear stretched out (green arrow). These observations suggest that some of the faulting occurred while the layered deposits were still soft and could undergo deformation, whereas other faults formed later when the layers must have been solidified and produced a clean break.

These layers are located in Meridiani Planum, a relatively flat area on the Martian equator. Opportunity landed on this plain to the southwest of this region, as shown on the geology map to the left. The white cross in the southwest corner indicates Opportunity’s landing site, with Endeavour Crater just to the southeast. The white box in the northwest shows where the faulted layered deposits are located. Based on the scale of the map, this places Opportunity approximately 400 miles away.

What exactly caused these distinct faults remains unknown. The likely cause would be a earthquake, but since Mars does not have plate tectonics like the Earth, earthquakes would have to be caused by other geological processes not yet studied.

To my eye, they look like cracks in a mirror, though this provides no real explanation other than it illustrates how cool the image is.

Curiosity

Since my last update on September 6, Curiosity has continued its travels up and across Vera Rubin Ridge, a geological bedding plain dubbed the Hematite Unit. The panorama above, created by reader Phil Veerkamp, shows the view looking up the ridge slope. If you click on it you can see the full resolution image, with lots of interesting geological details.

The panorama below, also created by Veerkamp, shows the view on Sol 1866, two weeks later, as the slope begins to flatten out and the distant foothills of Mount Sharp become visible. (If you click on the image you can see a very slightly reduced version of the full resolution panorama.) This image also shows the next change in geology. From orbit the Hematite Unit darkens suddenly at its higher altitudes, and Curiosity at this point was approaching that transition. The rover is now, on Sol 1876, sitting on that boundary, where they will spend a few days making observations before moving on.

The image on the right shows Curiosity’s approximate position, about halfway across the Hematite Unit and with the rover’s approximate future route indicated, as shown in this October 3, 2016 press release.

In the two months since my last rover update the Curiosity engineering team has spent a lot of time imaging and studying the Hematite Unit. They have also spent a considerable amount of time doing new tests on the rover’s drill in an effort to get around its stuck feed mechanism in order to drill again. Only yesterday they took another series of close-up images of the drill in this continuing effort.

As indicated by the October 3 2016 press release, the rover still has a good way to go before it begins entering the distant canyons and large foothills. While they should leave the Hematite Unit and enter the Clay Unit beyond in only a few more months, I expect it will be at least a year before they pass through the Clay Unit and reach the much more spectacular Sulfate Unit, where the rover will explore at least one deep canyon as well as a recurring dark feature on a slope that scientists think might be a water seep.

“Not simply about one mission, [Genesis] is also the history of America’s quest for the moon… Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America’s greatest human triumphs.”
–San Antonio Express-News